Electric drive systems for large off-highway machines, such as mining trucks, typically include an alternator, or other electrical power generator, driven by an internal combustion engine. The alternator, in turn, supplies electrical power to a pair of electric drive motors connected to wheels of the machine. It should be appreciated that a significant amount of heat is generated during the operation of the electric drive system. Specifically, the alternator and the electric drive motors, along with various other electrical components, may generate a significant amount of heat and, as such, require cooling to prevent damage or failure. However, cooling of these components provides significant challenges due to space limitations, the relative positioning of each of the components, and the amount of cooling that is required.
U.S. Pat. No. 6,837,322 teaches a ventilation system for an electric drive vehicle utilizing a single centrifugal blower for cooling an alternator, a drive motor, and a control group component. Specifically, the blower is driven by the alternator and is configured to accelerate air in both a radial direction and an axial direction. At least one opening is formed in a perimeter portion of a housing of the blower for receiving the radial airflow, and at least one opening is formed in a side portion of the housing for receiving the axial airflow. Air is routed from these openings to each of the alternator, drive motor, and control group. Although this ventilation system may provide sufficient cooling for an electric drive machine having a specific configuration, it should be appreciated that a variety of electric drive systems exist, each having a unique configuration and, as such, being subject to unique requirements and spatial constraints. As a result, there is a continuing need for cooling systems having efficient designs that fit within limited space constraints of a machine and, further, provide reduced weight and cost. Further, there is a need for cooling systems having reduced pressure losses and more evenly distributed cooling flow in specific components, such as the electric drive motors.
The present disclosure is directed to one or more of the problems set forth above.